Package com.googlecode.objectify.cache

Class CachingAsyncDatastoreReaderWriter

java.lang.Object

com.googlecode.objectify.cache.CachingAsyncDatastoreReaderWriter

All Implemented Interfaces:

AsyncDatastoreReaderWriter

Direct Known Subclasses:

CachingAsyncDatastore, CachingAsyncTransaction

public abstract class CachingAsyncDatastoreReaderWriter
extends Object
implements AsyncDatastoreReaderWriter

A write-through memcache for Entity objects that works for both transactional and nontransactional sessions.

• Caches negative results as well as positive results.
• Queries do not affect the cache in any way.
• Transactional reads bypass the cache, but successful transaction commits will update the cache.
• This cache has near-transactional integrity. As long as DeadlineExceededException is not hit, cache should not go out of sync even under heavy contention.

Note: Until Google adds a hook that lets us wrap native Futureinvalid input: '<'?> implementations, you muse install the AsyncCacheFilter to use this cache asynchronously. This is not necessary for synchronous use of CachingDatastoreService, but asynchronous operation requires an extra hook for the end of a request when fired-and-forgotten put()s and delete()s get processed. If you use this cache asynchronously, and you do not use the AsyncCacheFilter, your cache will go out of sync.

Author:

Jeff Schnitzer invalid input: '<'[email protected]>

Constructor Summary

Constructors

Constructor	Description
CachingAsyncDatastoreReaderWriter()

Method Summary

Modifier and Type	Method	Description
Future<Void>	delete(Iterable<com.google.cloud.datastore.Key> keys)
protected abstract void	empty(Iterable<com.google.cloud.datastore.Key> keys)
Future<List<com.google.cloud.datastore.Key>>	put(Iterable<? extends com.google.cloud.datastore.FullEntity<?>> entities)
<T> com.google.cloud.datastore.QueryResults<T>	run(com.google.cloud.datastore.Query<T> query)
Future<com.google.cloud.datastore.AggregationResults>	runAggregation(com.google.cloud.datastore.AggregationQuery query)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.googlecode.objectify.impl.AsyncDatastoreReaderWriter

get, get, put

Constructor Details

CachingAsyncDatastoreReaderWriter

public CachingAsyncDatastoreReaderWriter()

Method Details

empty

protected abstract void empty(Iterable<com.google.cloud.datastore.Key> keys)

delete

public Future<Void> delete(Iterable<com.google.cloud.datastore.Key> keys)

Specified by:

delete in interface AsyncDatastoreReaderWriter

run

public <T>
com.google.cloud.datastore.QueryResults<T> run(com.google.cloud.datastore.Query<T> query)

Specified by:

run in interface AsyncDatastoreReaderWriter

put

public Future<List<com.google.cloud.datastore.Key>> put(Iterable<? extends com.google.cloud.datastore.FullEntity<?>> entities)

Specified by:

put in interface AsyncDatastoreReaderWriter

runAggregation

public Future<com.google.cloud.datastore.AggregationResults> runAggregation(com.google.cloud.datastore.AggregationQuery query)

Specified by:

runAggregation in interface AsyncDatastoreReaderWriter